Method and apparatus for detecting a pedestrian by a vehicle during night driving

ABSTRACT

A method and an apparatus for detecting a pedestrian by a vehicle during night driving are provided, in which the apparatus includes: a first camera configured to take a first image including color information of a vicinity of the vehicle during night driving; a second camera configured to take a second image including thermal distribution information of the vicinity of the vehicle; a pedestrian detector configured to detect a non-pedestrian area by using the color information from the first image and detect a pedestrian area by excluding the non-pedestrian area from the second image; and a display configured to match and display the pedestrian area on the second image.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims under 35 U.S.C. §119(a) priorityfrom Korean Patent Application No. 10-2014-0110943, filed on Aug. 25,2014 in the Korean Intellectual Property Office, the disclosure of whichis incorporated herein in its entirety by reference.

BACKGROUND

(a) Field of the Invention

The present invention relates to a method and apparatus for detecting apedestrian by a vehicle during night driving, in which a color image andan infrared image are obtained, and a pedestrian area is detected byexcluding a non-pedestrian area from the infrared image usinginformation of the color image.

(b) Description of the Related Art

A vehicle vision system takes a color image of the vicinity of a vehiclethrough a camera mounted on the vehicle and displays it. For detectingan object (a vehicle, a pedestrian, etc.), this color image ensures acertain degree of performance during the daytime, but the performancefor detecting an object such as a pedestrian/animal is significantlyreduced at nighttime.

In order to solve the problem, conventionally, a vehicle night visionsystem, which applies a far-infrared camera or a near-infrared camera,etc. taking a thermal image by using the thermal property generated froma human body, has been proposed. However, because the thermal image isdetected as a black and white image, substantial information may be lostand thus erroneous detection is increased.

SUMMARY

A method and an apparatus for detecting a pedestrian by a vehicle duringnight driving includes obtaining a color image and an infrared image,and detecting a pedestrian area by excluding a non-pedestrian area fromthe infrared image using information of the color image.

According to an embodiment of the present invention, an apparatus fordetecting a pedestrian by a vehicle during night driving includes: afirst camera configured to take a first image including colorinformation of a vicinity of the vehicle during night driving; a secondcamera configured to take a second image including thermal distributioninformation of the vicinity of the vehicle; a pedestrian detectorconfigured to detect a non-pedestrian area by using the colorinformation from the first image and detect a pedestrian area byexcluding the non-pedestrian area from the second image; and a displayconfigured to match and display the pedestrian area on the second image.

Also, the second camera is implemented by one of an infrared camera, afar-infrared camera, and a near-infrared camera.

Also, the pedestrian detector includes an image matcher configured tomatch the first image and the second image, a non-pedestrian areadetector configured to detect the area which a color value is more thana reference value as the non-pedestrian area from the first image basedon the color information of the first image, an attention area extractorconfigured to extract an attention area by excluding the non-pedestrianarea from the second image, and a pedestrian area extractor configuredto extract the pedestrian area from the attention area.

Also, the image matcher calculates a real coordinate of an object from acoordinate of the first image by using inside and outside parameters ofthe first camera and a real distance between a virtual starting pointand the object

Also, the image matcher calculates a corresponding coordinate of thesecond image corresponding to the coordinate of the first image by usingthe real coordinate of the object, inside and outside parameters of thesecond camera, and the real distance.

Also, the virtual starting point is a central point between pointsrepresenting locations of the first and second cameras, in which avertical line from starting points of the first camera and the secondcamera and planes of the first image and the second image meet.

An method for detecting a pedestrian by a vehicle during night drivingaccording to an embodiment of the present invention includes the stepsof: taking a first image and a second image of a vicinity of the vehiclethrough a first camera and a second camera, respectively, during nightdriving; matching the first image and the second image; detecting anon-pedestrian area by using a color information of the first image;excluding the non-pedestrian area from the second image;

detecting a pedestrian area from the second image excluding thenon-pedestrian area; and matching and displaying the pedestrian area onthe first image.

Also, the step of matching the first image and the second image includessteps of: calculating a real coordinate of an object from a coordinateof the first image by using inside and outside parameters of the firstcamera and a real distance between a virtual starting point and theobject, and calculating a corresponding coordinate of the second imagecorresponding to a coordinate of the first image by using the realcoordinate of the object, inside and outside parameters of the secondcamera and the real distance.

Also, the virtual starting point is a central point between the points,which a vertical line from starting points of the first camera and thesecond camera and planes of the first image and the second image meet.

Also, the step of detecting a non-pedestrian area detects an area whicha color value is more than a reference value as the non-pedestrian areafrom the first image.

Since the present invention obtains a color image and an infrared imageand detects a pedestrian area by excluding a non-pedestrian area fromthe infrared image using information of the color image, the calculationamount and the probability of an erroneous detection can be reduced andthus reliable information can be provided.

Further, the present invention can be combined with the existing frontcamera and thus the performance is improved without any additional cost

Further, since the present invention excludes the non-pedestrian areafrom the image, the existing pedestrian detection algorithm can beapplied and the calculation speed of a pedestrian detection can beimproved.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will be more apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a block configuration diagram of an apparatus for detecting apedestrian by a vehicle during night driving according to an embodimentof the present invention.

FIG. 2 a is diagram showing the geometric relation between two imagesobtained by two cameras related to the present invention.

FIG. 2 b is flow chart showing a process for calculating a correspondingcoordinate between cameras of the image matcher shown in FIG. 1.

FIG. 3 is a flow chart showing a method for detecting a pedestrian by avehicle during night driving according to an embodiment of the presentinvention.

FIG. 4 a to FIG. 4 d are exemplary diagrams showing the image processingresult for each of steps of a night pedestrian detection process.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the embodiments of the present invention will be describedin detail with reference to the drawings.

It is understood that the term “vehicle” or “vehicular” or other similarterm as used herein is inclusive of motor vehicles in general such aspassenger automobiles including sports utility vehicles (SUV), buses,trucks, various commercial vehicles, watercraft including a variety ofboats and ships, aircraft, and the like, and includes hybrid vehicles,electric vehicles, plug-in hybrid electric vehicles, hydrogen-poweredvehicles and other alternative fuel vehicles (e.g. fuels derived fromresources other than petroleum). As referred to herein, a hybrid vehicleis a vehicle that has two or more sources of power, for example bothgasoline-powered and electric-powered vehicles.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items.

Further, the control logic of the present invention may be embodied asnon-transitory computer readable media on a computer readable mediumcontaining executable program instructions executed by a processor,controller or the like. Examples of computer readable media include, butare not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes,floppy disks, flash drives, smart cards and optical data storagedevices. The computer readable medium can also be distributed in networkcoupled computer systems so that the computer readable media is storedand executed in a distributed fashion, e.g., by a telematics server or aController Area Network (CAN).

FIG. 1 is a block configuration diagram of an apparatus for detecting apedestrian by a vehicle during night driving according to an embodimentof the present invention, FIG. 2 a is diagram showing the geometricrelation between two images obtained by two cameras related to thepresent invention, and FIG. 2 b is flow chart showing a process forcalculating a corresponding coordinate between cameras of the imagematcher shown in FIG. 1.

Referring to FIG. 1, an apparatus for detecting a pedestrian accordingto the present invention includes a first camera 10, a second camera 20,a pedestrian detector 30 and a display 40.

The first camera 10 takes a first image including color information ofthe vicinity of a vehicle during night driving. The first camera 10 canbe implemented by a CCD (Charge Coupled Device) camera and the like.

The second camera 20 takes a second image including thermal distributioninformation of the vicinity of the vehicle. The second camera 20 can beimplemented by an infrared camera, a far-infrared camera, anear-infrared camera, and the like.

The first camera 10 and the second camera 20 are mounted in pairs on atleast one of the front, rear, and side of the vehicle. The first camera10 and second camera 20 are arranged in two different points of the sameplane (for example, front). In particular, the first camera 10 and thesecond camera 20 obtain the image of the same scene from the differentpoints from each other.

The pedestrian detector 30 detects a non-pedestrian area from the firstimage and detects the pedestrian area by excluding the non-pedestrianarea from the second image. This pedestrian detector 30 can beimplemented by an image processor.

The pedestrian detector 30 includes an image matcher 31, anon-pedestrian area detector 32, an attention area extractor 33, and apedestrian area extractor 34.

The image matcher 31 matches the first image and the second image byusing viewpoint change technology. In other words, the image matcher 31mutually matches the coordinates of the first image and the second imageobtained from the different points from each other.

The process which the image matcher 31 calculates the correspondingcoordinates between the first image and the second image will bedescribed with reference to FIG. 2 a and FIG. 2 b.

Referring to FIG. 2 a, one point P in the three dimensional space isprojected onto an image coordinate p in the first image, and isprojected onto an image coordinate p′ in the second image. Also, acentral point between the points, in which a vertical line from thestarting points of two cameras and the planes of the first image and thesecond image meet, is assumed as a virtual starting point, and thedistance from the virtual starting point to the point P is assumed as areal distance Z. If the image coordinate p of the first image isinputted, in order to calculate the image coordinate of thecorresponding p′ in the second image, if the image coordinate p(x, y) ofthe first image is inputted, the image matcher 31 calculates the realcoordinate (X, Y, Z) of the point P by using the inside and outsideparameter of the first camera 10 and the real distance Z.

The image matcher 31 calculates the image coordinate p′(u, v) of thesecond image corresponding to the image coordinate p(x, y) of the firstimage by using the real coordinate (X, Y, Z) of the point P, the insideand outside parameter of the second camera 10, and the real distance Z.

The non-pedestrian detector 32 detects the non-pedestrian area from thefirst image by using the color information (hue information) of thefirst image. At this time, the non-pedestrian area detector 32 detectsthe area which the color value is more than the reference value from thefirst image as the non-pedestrian area.

The attention area extractor 33 excludes the non-pedestrian areadetected by the non-pedestrian area detector 32 from the second image.In particular, the second image excluding the non-pedestrian areabecomes the attention area capable of detecting the pedestrian area.

The pedestrian area extractor 34 extracts the pedestrian area from thesecond image excluding the non-pedestrian area. At this time, thepedestrian area extractor 34 extracts the pedestrian area from thesecond image by using a feature detection and learning algorithm (apedestrian detection algorithm).

The display 40 matches and displays the pedestrian area extracted by thepedestrian are extractor 34 on the second image. This display 40 can beimplemented by LCD (Liquid Crystal Display), LED (Light Emitting Diode)display, HUD (Head-Up Display), a transparent display and the like.

FIG. 3 is a flow chart showing a method for detecting a pedestrian by avehicle during night driving according to an embodiment of the presentinvention, and FIG. 4 a to FIG. 4 d are exemplary diagrams showing theimage processing result for each of steps of a night pedestriandetection process.

First, the pedestrian detector 30 of a pedestrian detection apparatustakes the first image and the second image of the vicinity (for example,front, rear, or side) of a vehicle through the first camera 10 and thesecond camera 20 during night driving (S11). At this time, the firstimage and the second image is the images taken in the different pointsfrom each other, the first image (color image) includes the colorinformation for the vicinity of a vehicle, and the second image includesthe thermal distribution information for the vicinity of a vehicle.

The image matcher 31 of the pedestrian detector 30 matches the imagecoordinate of the second image corresponding to the image coordinate ofthe first image (S12). In other words, the image matcher 31 calculatesthe real coordinate of the object from the coordinate of the first imageby using the inside and the outside parameter of the first camera 10 andthe real distance between the virtual starting point and the object, andcalculates the corresponding coordinate of the second imagecorresponding to the coordinate of the first image by using the realcoordinate of the object, the inside and the outside parameter of thesecond camera 20 and the real distance.

The non-pedestrian detector 32 detects the non-pedestrian area form thefirst image by using the color information of the first image (S13). Atthis time, the non-pedestrian area detector 32 detects the area whichthe color value is more than the reference value as the non-pedestrianarea in the first image. In particular, the non-pedestrian detector 32detects the bright area which is more than the reference as compared tothe vicinity as the non-pedestrian area as shown in FIG. 4 a.

The attention area extractor 33 excludes the non-pedestrian area fromthe second image (S14). For example, the attention area extractor 33detects the area of the far-infrared area corresponding to thenon-pedestrian area detected form the color image and deletes the areaas shown in FIG. 4 b.

The pedestrian area extractor 34 detects the pedestrian area form thesecond image excluding the non-pedestrian area (S15). Here, thepedestrian area extractor 34 detects the pedestrian area in thefar-infrared area excluding the non-pedestrian area by using a featuredetection and learning algorithm (pedestrian detection algorithm) asshown in FIG. 4 c.

The display 40 matches and displays the pedestrian area detected by thepedestrian detector 30 on the first image (S16). For example, thedisplay 40 matches and displays the pedestrian area detected from thefar-infrared image on the color image as shown in FIG. 4 d. Although thepresent invention has been described through specific exemplaryembodiments hereinabove, it may be variously modified without departingfrom the scope of the present invention. Accordingly, the scope of thepresent invention is not to be construed as being limited to theabove-mentioned exemplary embodiments, but is to be defined by thefollowing claims and equivalents thereto. When considering theabove-mentioned contents, it is to be considered that the presentinvention includes modifications and alternations thereof as long asthese modifications and alternations are within the scope of thefollowing claims and equivalents thereto.

What is claimed is:
 1. An apparatus for detecting a pedestrian by avehicle during night driving, comprising: a first camera configured totake a first image including color information of a vicinity of thevehicle during night driving; a second camera configured to take asecond image including thermal distribution information of the vicinityof the vehicle; a pedestrian detector configured to detect anon-pedestrian area by using the color information from the first imageand detect a pedestrian area by excluding the non-pedestrian area fromthe second image; and a display configured to match and display thepedestrian area on the second image.
 2. The apparatus of claim 1,wherein the first camera is implemented by one of an infrared camera, afar-infrared camera, and near-infrared camera.
 3. The apparatus of claim1, wherein the pedestrian detector comprises an image matcher configuredto match the first image and the second image, a non-pedestrian areadetector configured to detect an area in which a color value is morethan a reference value as the non-pedestrian area from the first imagebased on the color information of the first image, an attention areaextractor configured to extract an attention area by excluding thenon-pedestrian area from the second image, and a pedestrian areaextractor configured to extract the pedestrian area from the attentionarea.
 4. The apparatus of claim 3, wherein the image matcher calculatesa real coordinate of an object from a coordinate of the first image byusing inside and outside parameters of the first camera and a realdistance between a virtual starting point and the object.
 5. Theapparatus of claim 4, wherein the virtual starting point is a centralpoint between points representing locations of the first and secondcameras, in which a vertical line from the points of the first cameraand the second camera and planes of the first image and the second imagemeet.
 6. The apparatus of claim 4, wherein the image matcher calculatesa corresponding coordinate of the second image corresponding to thecoordinate of the first image by using the real coordinate of theobject, inside and outside parameters of the second camera, and the realdistance.
 7. The apparatus of claim 6, wherein the virtual startingpoint is a central point between points representing locations of thefirst and second cameras, in which a vertical line from the points ofthe first camera and the second camera and planes of the first image andthe second image meet.
 8. A method for detecting a pedestrian by avehicle during night driving, comprising the steps of: taking a firstimage and a second image of a vicinity of the vehicle through a firstcamera and a second camera, respectively, during night driving; matchingthe first image and the second image; detecting a non-pedestrian area byusing color information of the first image; excluding the non-pedestrianarea from the second image; detecting a pedestrian area from the secondimage excluding the non-pedestrian area; matching and displaying thepedestrian area on the first image.
 9. The method according to claim 8,wherein the step of matching the first image and the second imagefurther comprises steps of: calculating a real coordinate of an objectfrom a coordinate of the first image by using inside and outsideparameters of the first camera and a real distance between a virtualstarting point and the object; and calculating a correspondingcoordinate of the second image corresponding to the coordinate of thefirst image by using a real coordinate of the object, inside and outsideparameters of the second camera, and the real distance.
 10. The methodaccording to claim 9, wherein the virtual starting point is a centralpoint between points representing locations of the first and secondcameras, in which a vertical line from starting points of the firstcamera and the second camera and planes of the first image and thesecond image meet.
 11. The method according to claim 8, wherein the stepof detecting the non-pedestrian area includes detecting an area in whicha color value is more than a reference value as the non-pedestrian areafrom the first image.